docs: def _read_metadata(self, f, endianness):
          """
          Read the metadata for a DAQmx raw segment.  This is the raw
          DAQmx-specific portion of the raw data index.
          """
          self.data_type = types.tds_data_types[0xFFFFFFFF]
          self.dimension = types.Uint32.read(f, endianness)
          # In TDMS format version 2.0, 1 is the only valid value for dimension
          if self.dimension != 1:
              log.warning("Data dimension is not 1")
          self.chunk_size = types.Uint64.read(f, endianness)
          # size of vector of format changing scalers
          self.scaler_vector_length = types.Uint32.read(f, endianness)
          # Size of the vector
          log.debug("mxDAQ format scaler vector size '%d'" %
                    (self.scaler_vector_length,))
          if self.scaler_vector_length > 1:
              log.error("mxDAQ multiple format changing scalers not implemented")
  
          for idx in range(self.scaler_vector_length):
              # WARNING: This code overwrites previous values with new
              # values.  At this time NI provides no documentation on
              # how to use these scalers and sample TDMS files do not
              # include more than one of these scalers.
              self.scaler_data_type_code = types.Uint32.read(f, endianness)
              self.scaler_data_type = (
                  types.tds_data_types[self.scaler_data_type_code])
  
              # more info for format changing scaler
              self.scaler_raw_buffer_index = types.Uint32.read(f, endianness)
              self.scaler_raw_byte_offset = types.Uint32.read(f, endianness)
              self.scaler_sample_format_bitmap = types.Uint32.read(f, endianness)
              self.scale_id = types.Uint32.read(f, endianness)
  
          raw_data_widths_length = types.Uint32.read(f, endianness)
          self.raw_data_widths = np.zeros(raw_data_widths_length, dtype=np.int32)
          for cnt in range(raw_data_widths_length):
              self.raw_data_widths[cnt] = types.Uint32.read(f, endianness)